1. Field of the Invention
The present invention relates to an electromagnetic wave blocking member for a display apparatus, and more particularly, to an electromagnetic wave blocking member for a display apparatus which can simplify the manufacturing process, and improve an electromagnetic wave-blocking capacity.
2. Description of Related Art
As modern society becomes more information oriented, technology of parts and devices related to image displays is remarkably advancing, and these parts and devices are becoming widespread. Display apparatuses utilizing parts and devices related to photoelectronics are becoming significantly widespread and used for television apparatuses, monitor apparatuses of personal computers, and the like. Also, display apparatuses are becoming both larger and thinner. Plasma display panel (PDP) apparatuses are gaining popularity as next-generation display apparatuses to simultaneously satisfy a trend of becoming larger, and of becoming thinner, when compared with cathode-ray tubes (CRTs) representing existing display apparatuses. Also, the PDP apparatuses exhibit superior display characteristics such as display resolution, brightness, contrast ratio, an afterimage, a viewing angle, and the like.
In general, PDP apparatuses generate a gas discharge between electrodes by a direct current (DC) voltage or an alternating current (AC) voltage which are supplied to the electrodes. Here, ultraviolet light is generated, and then, a phosphor is excited by the ultraviolet light, thereby emitting light. As a result, the PDP apparatus has a defect in that an amount of emitted electromagnetic (EM) radiation and near infrared (NI) radiation with respect to a driving characteristic is great, and thus, EM radiation and NI radiation generated in the PDP apparatus may have harmful effects on human bodies, and cause sensitive equipment such as wireless telephones, remote controls, and the like, to malfunction. Therefore, in order to use the PDP apparatus, it is required to prevent emission of EM radiation and NI radiation emitted from the PDP apparatus from increasing to more than a predetermined level. For this purpose, an EM radiation shielding plate may be positioned on a front surface of a display screen of the PDP apparatus, and is required to have good see-through characteristics of the display screen.
However, the PDP apparatus is required to have various functions such as shielding NI radiation, reducing reflected light, enhancing color purity, and improving a contrast ratio in a bright room, as well as shielding the EM radiation. For this purpose, the PDP apparatus may adopt a PDP filter for simultaneously satisfying the above described functions. The PDP filter may be constructed such that a plurality of functional films such as an EM radiation-shielding film, an NI radiation-shielding film, a color correction film, an external light shielding film, and the like or multifunctional films such as an simultaneous EM-radiation shielding and NI-radiation shielding film, an both external light shielding and color correction film, and the like are stacked one upon another. Recently, attempts for simplifying the manufacturing process and reducing costs of PDP filters while simultaneously improving the above described functions have been made.
In existing EM radiation-shielding films, a scheme using a metal mesh, and a scheme coating a transparent electroconductive thin film may be used. As examples for the scheme using the metal mesh, a scheme for weaving a fiber coated with a metal and a scheme for etching a thin copper foil may be designated. Here, the mesh film obtained by the etching scheme may be generally used.
The scheme for etching the thin copper foil may be performed by the following processes. First, a copper film may be formed by a plating scheme, and then surface treatments may be executed on the copper film such as a blackening treatment for improvement of image quality, a surface ruggedness treatment for improvement of adhesive force, an antioxidant treatment, and the like. Next, the copper foil may be adhered on a polyethylene terephthalate (PET) film using an adhesive agent. Next, a pattern may be formed on the adhered copper film using a lithography method, and the copper film with the pattern may be partially etched, thereby fabricating the mesh film.
However, the mesh film fabricated by the etching scheme may have problems such as a high processing cost for the etching itself, a high material cost caused due to having to remove 90% or more of the copper, and the like. Alternatively, in order to reduce the dissipation of the copper caused by the etching scheme, a seed layer for electroless plating may be formed by the lithography method, and the copper may be formed on the seed layer by a plating method. However, there still arise problems such as complexity in the process performed by the lithography method.
Also, the scheme of coating the transparent electroconductive thin film disadvantageously has a poor EM radiation-shielding function in comparison with the scheme of using the metal mesh.